Hi, thanks for the heads-up! We haven't seen issues with memory usage in Firefox. Would you mind opening a ticket at help.getadblock.com so we can start investigating? Please include AdBlock's debugging information (https://help.getadblock.com/solution/articles/6000087856-how-do-i-give-you-debugging-information-). Thanks!
- Rhana, AdBlock Community Manager

Hi! That's a great question, and you're absolutely right to be cautious about the access you grant to software you install. In our case, AdBlock needs to be able to read the data on every web page you visit so that it can see what part of it is an ad it's going to need to block if possible or hide if not. Does that mean we store or use your personally identifiable information? Absolutely not. We're pretty big on privacy around here.

For more information about what kinds of information we can see and what we do with it, please see:
https://help.getadblock.com/solution/articles/6000087917-i-see-a-warning-that-adblock-can-access-my-data-and-browsing-activity-

I also encourage you to read our privacy policy, which goes into more detail:
https://getadblock.com/privacy

I hope this helps to reassure you! If you have any other questions, feel free to drop me a line at help@getadblock.com. :)

- Rhana, AdBlock Community Manager